After his mother died, Donny Callahan had problems relating to his domineering father, "Big Mike" Callahan. He fell in with the wrong crowd, first joining street gangs, and eventually allowing himself to be mutated into a superhuman enforcer, becoming the Squid.
In their first outing as supercriminals, the Squid and his girlfriend, Ms. Fortune, attacked Spider-Man on a rooftop. The Squid managed to spray Spider-Man with his ink and grab him with a tentacle, but Spider-Man unceremoniously tossed them off the roof.
After their defeat by Spider-Man, the criminals who empowered them turned on the Squid and Ms. Fortune, almost killing her. She broke up with the Squid, who was then hired by an Upper West Side crime boss to eliminate local businessmen who wouldn't sell their properties to him.
The Squid dragged "Old Man" Frenzetti into the sewers in front of his cigar shop, killing him. Later that night, Donny Callahan confronted his father in his bar, Callahan's. Angrily storming out when Peter Parker entered the bar, he slunk back into the sewers and attacked Miguel Vargas, coming up through the pipes in his coffee shop. Entangled in the Squid's tentacles, Vargas ran out into the street, yelling for help, as the Squid emerged from the sink. Before he could kill Vargas, however, the Squid was attacked by a baseball bat-wielding Mike Callahan. The Squid easily crushed the bat, but the distraction allowed Vargas to escape. Angered, he turned on Mike, but was blindsided by Spider-Man. Angrily recalling his past defeat by the web-slinger, the Squid lashed out at him, but was beaten back once more. Before Spider-Man could take him out, however, he was restrained by Mike, who pleaded with him to leave his son alone, claiming that he 'wasn't right in the head'. Taking advantage of his father's intervention, the Squid immobilized Spider-Man in his tentacles and began to strangle him. With the wall-crawler helpless, the Squid taunted Mike, telling him that he couldn't push him around anymore. To Donny's surprise, Mike agreed with him, and apologized for the way he'd treated him. The Squid released Spider-Man from his clutches, and began to advance on Mike. Spider-Man, still woozy, tried to stop the Squid, but he was felled again with a vicious tentacle swipe. Undaunted, Spider-Man rose again, and asked him, "Do you think your dad could have survived that one?". Donny realized that, for all the anger he felt towards his father, he still didn't want to kill him. He lowered his tentacles and stammered an apology. Donny, Mike, and Spider-Man talked long into the night...after which Donny was presumably taken away by the police.
The Squid was among a number of super-criminals recruited into a "villain army" by Hammerhead in order to take advantage of the raging superhero Civil War. Before they could begin doing so, however, their headquarters was raided by Iron Man and a small army of SHIELD agents. The Squid's fate in the ensuing melee is unknown.

After his mother died, Donny Callahan had problems relating to his domineering father, "Big Mike" Callahan. He fell in with the wrong crowd, first joining street gangs, and eventually allowing himself to be mutated into a superhuman enforcer, becoming the Squid.
In their first outing as supercriminals, the Squid and his girlfriend, Ms. Fortune, attacked Spider-Man on a rooftop. The Squid managed to spray Spider-Man with his ink and grab him with a tentacle, but Spider-Man unceremoniously tossed them off the roof.
After their defeat by Spider-Man, the criminals who empowered them turned on the Squid and Ms. Fortune, almost killing her. She broke up with the Squid, who was then hired by an Upper West Side crime boss to eliminate local businessmen who wouldn't sell their properties to him.
The Squid dragged "Old Man" Frenzetti into the sewers in front of his cigar shop, killing him. Later that night, Donny Callahan confronted his father in his bar, Callahan's. Angrily storming out when Peter Parker entered the bar, he slunk back into the sewers and attacked Miguel Vargas, coming up through the pipes in his coffee shop. Entangled in the Squid's tentacles, Vargas ran out into the street, yelling for help, as the Squid emerged from the sink. Before he could kill Vargas, however, the Squid was attacked by a baseball bat-wielding Mike Callahan. The Squid easily crushed the bat, but the distraction allowed Vargas to escape. Angered, he turned on Mike, but was blindsided by Spider-Man. Angrily recalling his past defeat by the web-slinger, the Squid lashed out at him, but was beaten back once more. Before Spider-Man could take him out, however, he was restrained by Mike, who pleaded with him to leave his son alone, claiming that he 'wasn't right in the head'. Taking advantage of his father's intervention, the Squid immobilized Spider-Man in his tentacles and began to strangle him. With the wall-crawler helpless, the Squid taunted Mike, telling him that he couldn't push him around anymore. To Donny's surprise, Mike agreed with him, and apologized for the way he'd treated him. The Squid released Spider-Man from his clutches, and began to advance on Mike. Spider-Man, still woozy, tried to stop the Squid, but he was felled again with a vicious tentacle swipe. Undaunted, Spider-Man rose again, and asked him, "Do you think your dad could have survived that one?". Donny realized that, for all the anger he felt towards his father, he still didn't want to kill him. He lowered his tentacles and stammered an apology. Donny, Mike, and Spider-Man talked long into the night...after which Donny was presumably taken away by the police.
The Squid was among a number of super-criminals recruited into a "villain army" by Hammerhead in order to take advantage of the raging superhero Civil War. Before they could begin doing so, however, their headquarters was raided by Iron Man and a small army of SHIELD agents. The Squid's fate in the ensuing melee is unknown. Afterward he was seen as part of the Hood's gang trying to prevent Mr. Negative forming an uprising.

The Squid can shift from his human form to a green-skinned, mouthless (sometimes) squid-like form. In this form, he possesses four (or six) extendable tentacles capable of restraining a superhuman with Class 10 strength. He can also spray his foes with a foul-smelling viscous ink, emitted from his hands. In his second encounter with Spider-Man, he secreted the ink constantly from his entire body - whether this was a reflection of his emotional state at the time or a delayed mutation is unknown. He can also apparently squeeze through narrow pipes, indicating that his Squid form has no bones (or more that they're just highly malleable, like the Cobra's).

After his mother died, Donny Callahan had problems relating to his domineering father, "Big Mike" Callahan. He fell in with the wrong crowd, first joining street gangs, and eventually allowing himself to be mutated into a superhuman enforcer, becoming the Squid.
In their first outing as supercriminals, the Squid and his girlfriend, Ms. Fortune, attacked Spider-Man on a rooftop. The Squid managed to spray Spider-Man with his ink and grab him with a tentacle, but Spider-Man unceremoniously tossed them off the roof.
After their defeat by Spider-Man, the criminals who empowered them turned on the Squid and Ms. Fortune, almost killing her. She broke up with the Squid, who was then hired by an Upper West Side crime boss to eliminate local businessmen who wouldn't sell their properties to him.
The Squid dragged "Old Man" Frenzetti into the sewers in front of his cigar shop, killing him. Later that night, Donny Callahan confronted his father in his bar, Callahan's. Angrily storming out when Peter Parker entered the bar, he slunk back into the sewers and attacked Miguel Vargas, coming up through the pipes in his coffee shop. Entangled in the Squid's tentacles, Vargas ran out into the street, yelling for help, as the Squid emerged from the sink. Before he could kill Vargas, however, the Squid was attacked by a baseball bat-wielding Mike Callahan. The Squid easily crushed the bat, but the distraction allowed Vargas to escape. Angered, he turned on Mike, but was blindsided by Spider-Man. Angrily recalling his past defeat by the web-slinger, the Squid lashed out at him, but was beaten back once more. Before Spider-Man could take him out, however, he was restrained by Mike, who pleaded with him to leave his son alone, claiming that he 'wasn't right in the head'. Taking advantage of his father's intervention, the Squid immobilized Spider-Man in his tentacles and began to strangle him. With the wall-crawler helpless, the Squid taunted Mike, telling him that he couldn't push him around anymore. To Donny's surprise, Mike agreed with him, and apologized for the way he'd treated him. The Squid released Spider-Man from his clutches, and began to advance on Mike. Spider-Man, still woozy, tried to stop the Squid, but he was felled again with a vicious tentacle swipe. Undaunted, Spider-Man rose again, and asked him, "Do you think your dad could have survived that one?". Donny realized that, for all the anger he felt towards his father, he still didn't want to kill him. He lowered his tentacles and stammered an apology. Donny, Mike, and Spider-Man talked long into the night...after which Donny was presumably taken away by the police.
The Squid was among a number of super-criminals recruited into a "villain army" by Hammerhead in order to take advantage of the raging superhero Civil War. Before they could begin doing so, however, their headquarters was raided by Iron Man and a small army of SHIELD agents. The Squid's fate in the ensuing melee is unknown.